At 4th level, a myrmidarch can use spellstrike to cast a single-target touch attack ranged spell and deliver it through a ranged weapon attack. Even if the spell can normally affect multiple targets, only a single missile, ray, or effect accompanies the attack. At 11th level, a myrmidarch using a multiple-target spell with this ability may deliver one ray or line of effect with each attack when using a full-attack action, up to the maximum allowed by the spell (in the case of ray effects). Any effects not used in the round the spell is cast are lost. This ability replaces spell recall and improved spell recall.
I guess I'm having a hard time rationalizing between RAW and the theater of the mind's eye- can you make a "ranged weapon attack" without using ammunition? I guess, the question is, are you shooting your spell through your weapon, or are you putting your spell on your ammunition?